Samuel Merrill III has served as a professor of mathematics at the University of Rochester and Wilkes University. He received a PhD in Mathematics from Yale University and an MS in Statistics from Pennsylvania State University.Bernard Grofman is Distinguished Research Professor of Political Science at the University of California, Irvine and the inaugural Jack W. Peltason Chair of Democracy Studies at the University of California, Irvine. Thomas L. Brunell is Professor of Political Science University of Texas at Dallas

Among the leading students of the increasing polarization of American politics, the authors of this important new book lay out a novel institutional perspective on the interaction between polarization in Congress and competition at the district level.

• Acknowledgements Part I: Where Did Polarization Come From and Why is it Getting Worse? Chapter 1. Making Sense of Polarization Chapter 2. How Does Party Discipline Generate Polarization? Chapter 3. Why, Even in Highly Competitive Districts, Are Candidate Positions so Different? Chapter 4. Heterogeneity across Districts and Within-district Partisan Gap and Proclivity Part II: Conseqences of PolarizationChapter 5. How Do Party Loyalty and Activist Influence Foster Mobilizing the Base?Chapter 6. Consequences of Polarized Politics Chapter 7. Discussion and Conclusions AppendicesAppendix to Chapter 1: Literature Review on Causes of Polarization Appendix to Chapter 2: The Party-constraint Model Appendix to Chapter 3: Relation between Candidate and District Ideology: Statistical and Theoretical Analyses Appendix to Chapter 4: Components of Legislative Polarization Appendix to Chapter 5: Derivations for the Appeal-to-the-Base Model Appendix to Chapter 6: Derivations relating to Chamber and Party Medians Bibliography

Samuel Merrill III has served as a professor of mathematics at the University of Rochester and Wilkes University. He received a PhD in Mathematics from Yale University and an MS in Statistics from Pennsylvania State University.Bernard Grofman is Distinguished Research Professor of Political Science at the University of California, Irvine and the inaugural Jack W. Peltason Chair of Democracy Studies at the University of California, Irvine. Thomas L. Brunell is Professor of Political Science University of Texas at Dallas

Among the leading students of the increasing polarization of American politics, the authors of this important new book lay out a novel institutional perspective on the interaction between polarization in Congress and competition at the district level.

• Acknowledgements Part I: Where Did Polarization Come From and Why is it Getting Worse? Chapter 1. Making Sense of Polarization Chapter 2. How Does Party Discipline Generate Polarization? Chapter 3. Why, Even in Highly Competitive Districts, Are Candidate Positions so Different? Chapter 4. Heterogeneity across Districts and Within-district Partisan Gap and Proclivity Part II: Conseqences of PolarizationChapter 5. How Do Party Loyalty and Activist Influence Foster Mobilizing the Base?Chapter 6. Consequences of Polarized Politics Chapter 7. Discussion and Conclusions AppendicesAppendix to Chapter 1: Literature Review on Causes of Polarization Appendix to Chapter 2: The Party-constraint Model Appendix to Chapter 3: Relation between Candidate and District Ideology: Statistical and Theoretical Analyses Appendix to Chapter 4: Components of Legislative Polarization Appendix to Chapter 5: Derivations for the Appeal-to-the-Base Model Appendix to Chapter 6: Derivations relating to Chamber and Party Medians Bibliography

Samuel Merrill III has served as a professor of mathematics at the University of Rochester and Wilkes University. He received a PhD in Mathematics from Yale University and an MS in Statistics from Pennsylvania State University.Bernard Grofman is Distinguished Research Professor of Political Science at the University of California, Irvine and the inaugural Jack W. Peltason Chair of Democracy Studies at the University of California, Irvine. Thomas L. Brunell is Professor of Political Science University of Texas at Dallas

Among the leading students of the increasing polarization of American politics, the authors of this important new book lay out a novel institutional perspective on the interaction between polarization in Congress and competition at the district level.

• Acknowledgements Part I: Where Did Polarization Come From and Why is it Getting Worse? Chapter 1. Making Sense of Polarization Chapter 2. How Does Party Discipline Generate Polarization? Chapter 3. Why, Even in Highly Competitive Districts, Are Candidate Positions so Different? Chapter 4. Heterogeneity across Districts and Within-district Partisan Gap and Proclivity Part II: Conseqences of PolarizationChapter 5. How Do Party Loyalty and Activist Influence Foster Mobilizing the Base?Chapter 6. Consequences of Polarized Politics Chapter 7. Discussion and Conclusions AppendicesAppendix to Chapter 1: Literature Review on Causes of Polarization Appendix to Chapter 2: The Party-constraint Model Appendix to Chapter 3: Relation between Candidate and District Ideology: Statistical and Theoretical Analyses Appendix to Chapter 4: Components of Legislative Polarization Appendix to Chapter 5: Derivations for the Appeal-to-the-Base Model Appendix to Chapter 6: Derivations relating to Chamber and Party Medians Bibliography